Spatial cues direct neuronal diversification with respect to OR gene selection. Spatial cues direct neuronal diversification with respect to OR gene selection. A–C, Location of ORs amplified from graft-derived OSNs by ISH. The cell designations D1-D5 refer to the single-cell RT-PCR results obtained using degenerate primers P26/P27 (compare Fig. 7); the dominant OR that was amplified from the isolated, graft-derived OSN is indicated. Scale bar in B2 equals 200 μm and also applies to A1 and B1. D, Assignment of OR expression to dorsal versus ventral region of the OE from all graft-derived OSNs; number of sequenced cells with the specified pattern of expression indicated above the respective bar in the graph. Expression pattern was localized by ISH performed here and/or previously published ISH studies of that specific OR and/or OR location computationally derived from bulk RNAseq, as performed by Tan and Xie (2018). Three weeks after ventral-to-ventral transplant, ORs isolated from all graft-derived OSNs by single-cell RT-PCR are normally expressed in the ventral OE. Three weeks after dorsal-to-ventral transplant, 62.5% of graft-derived OSNs express one or more ORs by single-cell RT-PCR that are normally expressed in the ventral OE. Four weeks after dorsal-to-ventral transplant, 80% of graft-derived neurons exclusively express ORs in the single-cell RNAseq analysis that are normally expressed in the ventral OE. Julie H. Coleman et al. J. Neurosci. 2019;39:814-832 ©2019 by Society for Neuroscience